"I accept that if I want to be elected PM there cannot be any doubt about my constitutional eligibility, pushed by the conspiracy theorists like the PM and the Member for Warringah (Tony Abbott)," Mr Shorten told parliament after Question Time.

"I offer this proof to the parliament today to put an end to baseless allegations, not reward them.

"I strongly believe that MPs and senators should not be to produce evidence to counter claims that are made completely without evidence."

Mr Shorten said providing the papers, which showed he renounced UK citizenship prior to his election in 2007, was a chance for Parliament to "draw a line in the sand" on the ongoing dual citizenship accusations.

"In an age of Twitter trolls, baseless online conspiracies, this is a chance for our parliament to declare we're bigger and better than this.

"To accept otherwise, to turn our back on the notion that a person making an allegation must have some evidence sets a dangerous precedent."

Mr Shorten said he suspected the Prime Minister and Coalition MPs knew their claims about his citizenship were false but it was simply a tactic to distract from the cloud over Deputy Prime Minister Barnaby Joyce's legitimacy.

He again called on Mr Joyce to stand aside until the High Court ruled on his case.

Government Minister Mathias Cormann told Sky News he agreed it was time to "draw a line in the sand".

"We shouldn't go after each other the way this has been happening in recent weeks," he said.

"We should let the High Court determine what the appropriate interpretation is of Section 44."

Mr Shorten's clarification came as two more MPs were referred to the High Court as dual citizenship drama continues to hijack Parliament.

Deputy Nationals leader Fiona Nash and senate powerbroker Nick Xenophon have both had their eligibility to sit in parliament referred to the High Court today after finding out they were British citizens by descent.

Their cases will now be heard along with five other MPs, including Mr Joyce, next month.

Mr Joyce's dual citizenship case dominated talk in Canberra this morning when Parliament resumed for a two week sitting.

Earlier today, Tony Abbott called on Mr Shorten to "shut up" about Mr Joyce unless he also provided proof that he renounced his British citizenship.

The former prime minister produced a letter proving he renounced his British citizenship in 1993 outside Parliament today in a bid to force the Opposition leader to do the same.

Mr Shorten had maintained that he was not a dual citizen but refused to provide his renunciation documents as proof.

"He should not be able to show his face anywhere in the country without being grilled uphill and down dale about his citizenship," Mr Abbott told reporters in Canberra this morning.

"He is making an enormous song and dance, he is trying to make the Parliament unworkable, and yet he is in exactly the same position as Barnaby Joyce.

"His father was born overseas, he says he has renounced his British citizenship.

"Well, show it or shut up.

"And if you can't show it, you should shut up and let the Deputy Prime Minister and the Government get on with the job of governing this country."

It comes after Deputy Labor leader Tanya Plibersek did not rule out party backbenchers walking out of Question Time if Mr Joyce fails to stand aside as Deputy Prime Minister or stands in as Acting Prime Minister later this week when Malcolm Turnbull is overseas.

Mr Joyce remained unfazed by the cloud over his future in politics and Labor's calls for him to stand aside.

"I'm working on the Solicitor General's advice," he said.

"If the Solicitor General had said to me 'You've got a less than likely chance', we would have gone straight to a by-election."

Mr Turnbull also slammed the Labor Party for playing "pathetic" political games over citizenship while the region faces the threat of nuclear war on the Korean peninsula.

"Australians will be sickened by the sight of the Labor Party's failure to recognise the priority of the Australian Parliament is to keep Australians safe and to support the opportunity, the economic opportunity that Australians deserve, and that requires the Parliament to focus on the real issues, rather than playing political games," he told ABC radio.

"The reality is we are facing on the Korean Peninsula the gravest threat to peace since the end of the Korean War. These are dangerous times.

"Now, what we Australians would expect is the Parliament to be resolute in support of the security of Australia."

Labor MP Tony Burke hit back at the Prime Minister's remarks, claiming Mr Turnbull was attempting to distract from the issue that Mr Joyce may not be eligible to sit in Parliament.

"North Korea is a sufficiently significant and grave international concern that it should be treated on its merits and treated specifically for the grave international concern that it is," Mr Burke said.

"But to have a Prime Minister wanting to use that as a veil to say 'Please go easy on Barnaby Joyce' is pathetic, simply pathetic from this Prime Minister."

He vowed Labor MPs would continue to fight against Mr Joyce remaining in Cabinet but said they would not stage a walk out.

Meanwhile, Labor frontbencher Katy Gallagher clarified her position today after The Daily Telegraph reported she may hold Ecuadorean citizenship.

Senator Gallagher said despite her mother having been born in the South American country, she had never received an Ecuadorean birth certificate and was never an Ecuadorean citizen.

She revealed she had sought legal advice from two experts to confirm earlier legal advice that she had never been an Ecuadorean citizen.

"I am not a citizen of Ecuador, I am not a citizen of the United Kingdom. I am eligible to serve in this parliament," she said.